Hi. I tried something similar and added a new client input value and the value is stored in an instance variable of a sprite which was added to "Sync", too.
I modified the Pong demo and when I added a new variable to the paddles it worked fine. But as soon as I add a new object with synced variables it seems nothing is sent to peers or received by the host anymore. :/
On Start of Layout:
The only difference between paddle and the tiledBG is that only the paddle (and only 1 object has to be?) has the "Multiplayer Associate" action.
When I open it in 2 browser windows and hit space on the Host the left number is increaded (in both windows) and if I hit it in the peer window the right number increases. But the value of the TiledBG (or other sprites I tried) is not updated. Does anyone know why or how to fix this?
btw: Is there a way to restore/redownload the original examples when you accidentially overwrite the sample file?